It is known to assemble an optoelectronic device with a material filling a cavity between a top cover and a backplane of the optoelectronics device. The fill material can provide a wide range of benefits. For instance, the fill material can help maintain a desired spacing between the top cover and the backplane and/or accommodate sag that may occur with relatively large panel displays. In further examples, the fill material may help protect the optoelectronic components from moisture, oxygen and/or other contaminants.